The presence of hydrogen sulfide in liquid kerosens, for example, is unacceptable even in small amounts. Yet as well as this Applicant can determine, little has been accomplished in developing any simple scavenging treatment for such non-aqueous liquids.
In U.S. Pat. No. 4,008,775, issued Feb. 22, 1977, and assigned to the same assignee as the present application, there is described a process in which specific porous iron oxides are used in drilling muds, primarily aqueous drilling muds to scavenge hydrogen sulfide (H.sub.2 S) released from a well in the course of a drilling operation. These iron oxides are described as having an ideal composition of substantially Fe.sub.3 O.sub.4, a particle size of about 1.5 to 60 microns and a surface area of at least ten times as great as magnetite (Fe.sub.3 O.sub.4) particles of equal size.
In co-pending application Ser. No. 44,026, filed May 31, 1979, and assigned to the same assignee as the present application, the same iron oxide (referred to as Compound A) as described in said patent is further characterized as having an amorphous Fe.sub.2 O.sub.3 (non-crystalline) moiety together with an Fe.sub.3 O.sub.4 crystalline phase. Further, in said application, other iron oxide particles (referred to as Compounds B and C), specifically, iron oxide waste dusts from open hearth or basic oxygen furnace steel-making operations, are described as being somewhat similar to the iron oxide particles of said patent in that they also have large surface areas and have an amorphous moiety of Fe.sub.2 O.sub.3 and an Fe.sub.3 O.sub.4 crystalline phase. However, they also have an Fe.sub.2 O.sub.3 crystalline phase. Still other iron oxide particles (referred to as Compound D) having a high surface area and an amorphous Fe.sub.2 O.sub.3 moiety and a crystalline Fe.sub.2 O.sub.3 phase are described in said application.
In the present application the designations Compounds A, B, C and D are intended to designate the same compounds identified and characterized in said co-pending application, the entire description of which is hereby incorporated by reference.
In said co-pending application, it is also described that the aforesaid iron oxide particles are useful for scavenging H.sub.2 S from hydrocarbon gases by bubbling such gases through a water suspension of such iron oxide particles, and a proces for practicing such scavenging of H.sub.2 S is claimed in said application. Said aplication also describes that in experiments utilizing a Parr pressure bomb apparatus, the recovery of sulfur-containing solids was fully as efficient where anhydrous diesel fuel was substituted for water in forming a test slurry of the type designated Compounds AD, residual water content of dessicated samples was less than 0.2%. However, this descriptive matter is not claimed in said co-pending application. Said description goes on to point out that "the results were not to be expected, in view of Simon and Reichelt [Z. Amerg. Allg. Chem. 319:962 (1964)] which teaches that iron oxide reacts with hydrogen sulfide by being first hydrated to FeOOH; that the hydrogen sulfide becomes ionized to form HS.sup.- and H.sup.+ ; and the reaction proceeds between the FeOOH and the HS.sup.- at an optimum water content of 18.0%".
It is described in U.S. Pat. No. 4,089,809, issued May 16, 1978, that H.sub.2 S can be removed from producer gas by passing the gas (at very high temperatures) through a bed of pellets composed of silica and Fe.sub.2 O.sub.3 ; and U.S. Pat. No. 4,201,751, issued May 6, 1908, describes that H.sub.2 S can be removed from coke oven gas by contacting the gas with a fluidized bed of particles of perlite containing steel-making dust comprising Fe.sub.2 O.sub.3 and an alkaline material such as lime under very turbulent conditions. However, applicant is unaware of any published information which teaches that H.sub.2 S can be scavenged from substantially non-aqueous liquid systems using iron oxides, much less the iron oxides which have been found to be useful in the practice of the present invention.